After MANY MANY iterations (Mogics Bagel, Too many Anker chargers to count, ZenTofu Maru and Masa, and on and on, I've settled on this rather small, relatively inexpensive ($38 as I write this) charger.
I think I found out about this in the USB-C thread.
Pro:
Small 2.08x2.08x1.2 vs 1.49x1.38x1.62 for the Anker 713 with only one port. (Anker 735 has three ports but is a bit longer in its longest dimension, 2.6", and doesn't have the snap-on adapters).
66w - plenty for a macbook air and tablet and phone.
2x USB C and 1x USB A
Folding plugs
Sturdy snap on plug Adapter for UK and Europe.
Con:
May fall out of wall - problem with most chargers of this type.
The problem with most standalone plug adapters is that they are too loose, or the weight of the charger pulls them out of the wall. This one has been quite sturdy and the Euro plug adapter stays put even in really loose airplane power ports.